_ Git - rapid-gossip-sync-server/blob - src/verifier.rs

   1 use std::convert::TryInto;
   2
   3 use bitcoin::{BlockHash, TxOut};
   4 use bitcoin::blockdata::block::Block;
   5 use bitcoin::hashes::Hash;
   6 use lightning::chain;
   7 use lightning::chain::AccessError;
   8 use lightning_block_sync::BlockSource;
   9 use lightning_block_sync::http::BinaryResponse;
  10 use lightning_block_sync::rest::RestClient;
  11
  12 use crate::config;
  13
  14 pub(crate) struct ChainVerifier {
  15         rest_client: RestClient,
  16 }
  17
  18 struct RestBinaryResponse(Vec<u8>);
  19
  20 impl ChainVerifier {
  21         pub(crate) fn new() -> Self {
  22                 ChainVerifier {
  23                         rest_client: RestClient::new(config::bitcoin_rest_endpoint()).unwrap(),
  24                 }
  25         }
  26
  27         fn retrieve_block(&self, block_height: u32) -> Result<Block, AccessError> {
  28                 tokio::task::block_in_place(move || { tokio::runtime::Handle::current().block_on(async move {
  29                         let uri = format!("blockhashbyheight/{}.bin", block_height);
  30                         let block_hash_result =
  31                                 self.rest_client.request_resource::<BinaryResponse, RestBinaryResponse>(&uri).await;
  32                         let block_hash: Vec<u8> = block_hash_result.map_err(|error| {
  33                                 eprintln!("Could't find block hash at height {}: {}", block_height, error.to_string());
  34                                 AccessError::UnknownChain
  35                         })?.0;
  36                         let block_hash = BlockHash::from_slice(&block_hash).unwrap();
  37
  38                         let block_result = self.rest_client.get_block(&block_hash).await;
  39                         let block = block_result.map_err(|error| {
  40                                 eprintln!("Couldn't retrieve block {}: {:?} ({})", block_height, error, block_hash);
  41                                 AccessError::UnknownChain
  42                         })?;
  43                         Ok(block)
  44                 }) })
  45         }
  46 }
  47
  48 impl chain::Access for ChainVerifier {
  49         fn get_utxo(&self, _genesis_hash: &BlockHash, short_channel_id: u64) -> Result<TxOut, AccessError> {
  50                 let block_height = (short_channel_id >> 5 * 8) as u32; // block height is most significant three bytes
  51                 let transaction_index = ((short_channel_id >> 2 * 8) & 0xffffff) as u32;
  52                 let output_index = (short_channel_id & 0xffff) as u16;
  53
  54                 let block = self.retrieve_block(block_height)?;
  55                 let transaction = block.txdata.get(transaction_index as usize).ok_or_else(|| {
  56                         eprintln!("Transaction index {} out of bounds in block {} ({})", transaction_index, block_height, block.block_hash().to_string());
  57                         AccessError::UnknownTx
  58                 })?;
  59                 let output = transaction.output.get(output_index as usize).ok_or_else(|| {
  60                         eprintln!("Output index {} out of bounds in transaction {}", output_index, transaction.txid().to_string());
  61                         AccessError::UnknownTx
  62                 })?;
  63                 Ok(output.clone())
  64         }
  65 }
  66
  67 impl TryInto<RestBinaryResponse> for BinaryResponse {
  68         type Error = std::io::Error;
  69
  70         fn try_into(self) -> Result<RestBinaryResponse, Self::Error> {
  71                 Ok(RestBinaryResponse(self.0))
  72         }
  73 }